Question map
Not attempted Correct Incorrect ★ Bookmarked
Loading…
Q24 (IAS/2009) Science & Technology › Basic Science (Physics, Chemistry, Biology) › Genetics and evolution Answer Verified

In the context of genetic disorders, consider the following : A woman suffers from colour blindness while her husband does not suffer from it. They have a son and a daughter. In this context, which one of the following statements is most probable) correct ?

Result
Your answer: —  Â·  Correct: D
Explanation

Colour blindness (most commonly red–green) is an X‑linked recessive condition. An affected woman must have two mutant X chromosomes (XcXc) while her normal husband is X+Y. All children inherit an X from their mother regardless of sex [1], so every child receives a mutant X from her. Sons receive the father’s Y and thus are XcY — they will express the recessive colour‑blind trait. Daughters receive the father’s normal X and the mother’s mutant X, becoming X+Xc — heterozygous carriers who typically do not show the recessive phenotype. Therefore the most probable outcome is an affected son and an unaffected (carrier) daughter (option 4) [2].

Sources

  1. [1] Science , class X (NCERT 2025 ed.) > Chapter 8: Heredity > 8.2.4 Sex Determination > p. 132
  2. [2] https://www.ncbi.nlm.nih.gov/books/NBK557383/
How others answered
Each bar shows the % of students who chose that option. Green bar = correct answer, blue outline = your choice.
Community Performance
Out of everyone who attempted this question.
75%
got it right
✓ Thank you! We'll review this.

SIMILAR QUESTIONS

IAS · 2021 · Q76 Relevance score: 3.89

In the context of hereditary diseases, consider the following statements : 1. Passing on mitochondrial diseases from parent to child can be prevented by mitochondrial replacement therapy either before or after in vitro fertilization of egg. 2. A child inherits mitochondrial diseases entirely from mother and not from father. Which of the statements given above is/are correct?

CDS-I · 2005 · Q70 Relevance score: 2.95

Consider the following eye disorders 1. Cataract 2. Colour blindness 3. Night blindness Which of the above disorders is/are essentially genetic in nature ?

IAS · 2010 · Q107 Relevance score: 2.19

In a group of five persons A, B, C, D and E, there is a professor, a doctor and lawyer. A and D are unmarried ladies, and do not work. Of the married couple in the Group, E is the husband. B is the brother of A and is neither a doctor nor a lawyer. Who is the professor?

CDS-I · 2010 · Q112 Relevance score: 2.05

Consider the following statements 1. A person with myopia can see distant objects distinctly but cannot see nearby objects clearly. 2. A person with hypermetropia cannot see distant objects clearly. 3. A person with presbyopia can see nearby objects without corrective glasses. Which of the statements given above is/are not correct ?

CAPF · 2008 · Q6 Relevance score: 1.86

Consider the following statements : 1. In a person suffering from myopia, the image of a distant object is formed behind the retina. 2. Myopia can be corrected by using a concave lens. Which of the above statements is/are correct ?